Engine with fluidic variable swirl port

A fluidic variable swirl intake port for an internal combustion engine, said port comprising

• a circular throat centered on a valve axis and terminating along the axis in an annular valve seat,
• an entry chamber surrounding the valve axis on the other side of the throat from the valve seat, said chamber being open along one side in a plane normal to said axis and having the remaining sides defined by a curved wall approximately centered near the axis and providing substantial volume surrounding the axis for flow through the throat,
• an inlet duct extending from the open side of the entry chamber at a substantial angle laterally from the valve axis, said duct having generally straight side walls extending tangent to the entry chamber defining curved wall and generally parallel roof and floor portions connecting the side walls, and
• a control port extending to the inlet duct through one of the side walls at a predetermined substantial distance from the valve axis for the delivery of control fluid into the port laterally to the direction of inlet flow through the duct to urge the entering flow toward one side of the duct and the entry chamber, thereby creating substantial swirl in the fluid flow entering the valve throat and passing by the valve seat.

A combination in an internal combustion engine of

• a fluidic variable swirl intake port having a valve axis and a control port opening through a side of the port at a substantial distance from the valve axis wherein entry of small amounts of control fluid into the intake port through the control port is effective to deflect the main charge flow through the intake port and create swirl of incoming charges entering an associated engine cylinder,
• an inlet duct connected with the intake port for conducting incoming charges thereto, said inlet duct including a throttle adjustable to vary the mass flow of incoming charges to the port, the moving of said throttle toward a closed position causing increasing vacuum in the intake port, and
• conduit means connected with the control port for conducting control fluid through the side of the intake port, the mass of control fluid delivered being variable at least in part as a function of the level of vacuum existing in the intake port,
• whereby control fluid flow increases as the throttle is closed so that, as the mass of incoming charges is reduced, the cylinder swirl is correspondingly increased.